OBJECTIVES: The projects in this Center proposal will require anatomical analysis of both gross and microscopic differences between wild type and mutant mice as related to drug addition. Gross differences and histological assays (i.e. Nissl staining, hematoxylin and eosin staining, and luxol fast blue staining) will be carried out in the laboratory of Dr. Westenbroek. The projects in this Center proposal will also require the use of confocal microscopy to determine changes in the localization and expression of various proteins in regions of the central nervous system in wild type and mutant mice as related to drug addiction. Confocal microscopy will be essential for determining whether these various proteins are expressed on the cell surface or in other cellular compartments. Two confocal microscopes are available in the W.M. Keck Imaging Facility located in the Health Sciences Building at the University of Washington. Dr. Ruth Westenbroek currently provides scientific oversight at the facility and has an extensive anatomy background and experience in preparation of tissue for immunocytochemistry. Dr. Westenbroek will be the PI on the Anatomical Core and will provide guidance in immunocytochemical procedures, proper controls, anatomical analysis, and will provide assistance in image analysis between control animals and experimental animals. Ms. Paulette Brunner currently provides technical support at the W.M. Keck Facility. The Imaging Center has recently acquired a new Leica TCS Spectral Confocal Microscope and Multiphoton Imaging System and Ms. Brunner will be responsible for training the individual investigators on this new system and over the long term provide assistance with image collection when necessary on both confocal microscopes located in the facility. Ms. Brunner is very adept at using image analysis software (i.e. MetaMorph, MetaFluor, NIH Image) and will assist the individual investigators in this area. In addition, Ms. Brunner will be responsible for scheduling and maintenance of the confocal microscopes, computers for image analysis and printers. The guidance and hands on help of Dr. Westenbroek and Ms. Brunner will allow the investigators quick and easy access to analysis of changes in anatomical localization associated with drug addiction.